Democrats were trounced in Tuesday’s state legislature election, despite the president’s heavy investment of time in the state.

Of all the noise of this week’s state election results, what mattered most for Election 2012 came out of Virginia. It was the sound of the air leaking out of the Plouffe plan.

That would be David Plouffe, President Obama’s former campaign manager and current senior strategist, who is focused today on how to cobble together 270 electoral votes for re-election. That’s proving tough, what with the economy hurting Mr. Obama in states like Ohio, Indiana and Pennsylvania that he won in 2008. The White House’s response has been to pin its hopes on a more roundabout path to electoral victory, one based on the Southern and Western states Mr. Obama also claimed in 2008.

States like Virginia. Mr. Obama was the first Democrat to win Virginia since 1964; he beat John McCain by seven percentage points; and he did so on the strength of his appeal to Northern Virginia’s many white-collar independents. Along with victories in North Carolina, Colorado and Nevada, the Obama Old Dominion win in 2008 inspired a flurry of stories about how Democrats had forever altered the political map.

So the White House is pouring resources into what Tim Kaine, the state’s former Democratic governor, now pridefully refers to as Democrats’ “New Dominion.” The Obama campaign has held some 1,600 events in the state in the last half-year alone. Only last month Mr. Obama hopped a three-day bus trip through Virginia and North Carolina. Obama officials keep flocking to the state, and Tuesday’s election was to offer the first indication of how these efforts are succeeding.

Let’s just say the New Dominion is looking an awful lot like the Old Dominion. If anything, more so.

Virginia Republicans added seven new seats to their majority in the House of Delegates, giving them two-thirds of that chamber’s votes—the party’s largest margin in history. The GOP also took over the Virginia Senate in results that were especially notable, given that Virginia Democrats this spring crafted an aggressive redistricting plan that had only one aim: providing a firewall against a Republican takeover of that chamber. Even that extreme gerrymander didn’t work.

Every Republican incumbent—52 in the House, 15 in the Senate—won. The state GOP is looking at unified control over government for only the second time since the Civil War. This is after winning all three top statewide offices—including the election of Gov. Bob McDonnell—in 2009, and picking off three U.S. House Democrats in last year’s midterms.

Topline figures aside, what ought to really concern the White House was the nature of the campaign, and the breakout of Tuesday’s election data. Mr. Obama may have big plans for Virginia, but the question is increasingly: him and what army?

Elected state Democrats—who form the backbone of grass-roots movements—couldn’t distance themselves far enough from Mr. Obama in this race. Most refused to mention the president, to defend his policies, or to appear with him. The more Republicans sought to nationalize the Virginia campaign, the more Democrats stressed local issues.

State House Minority Leader Ward Armstrong felt compelled to run an ad protesting that it was a “stretch” for his GOP opponent to “compare me to Barack Obama.” After all, he was “pro-life, pro-gun and I always put Virginia first.” (Mr. Armstrong lost on Tuesday.)

Virginia Democrats were happy to identify with one top official: Republican Gov. Bob McDonnell, who is providing a lesson in the benefits of smart GOP governance in battleground states. Criticized as being too socially conservative for Virginia when he was elected in 2009, Mr. McDonnell has won over voters by focusing on the economy and jobs. His approval ratings are in the 60s, and he helped raise some $5 million for local candidates. He’s popular enough that Democrats took to including pictures of him in their campaign literature, and bragging that they’d worked with him.

Mr. McDonnell has been particularly adept at connecting with the independent, white-collar voters Mr. Obama used to win Virginia in 2008. That crowd lives in North Virginia’s booming exurb counties of Prince William and Loudoun, and presidential races hinge on their votes. Mr. Obama’s 2008 victory in Virginia rested on his significant wins in both Loudoun (8%) and Prince Williams (16%).

Yet Tuesday’s results showed the extent to which that support has reversed. Loudoun in particular proved an unmitigated rout for Democrats. Republicans won or held three of four of the county’s Senate seats. It swept all seven of the county’s House seats. It won all nine slots on the county’s Board of Supervisors, and pretty much every other county office. In Prince William, the story was much the same. This is what happens when a recent Quinnipiac poll shows Mr. Obama’s approval rating among Virginia independents at 29%.

Democrats are now arguing that turnout (about 30%) was too low to prove anything, but then again, the particularly low Democratic turnout suggests that, on top of everything else, the White House really does face an enthusiasm gap. It’s still got time to try to remedy that problem, and some other Virginia fundamentals. But going by Tuesday’s results, Mr. Plouffe might need to start considering Electoral Plan C.